Origin of Cultured Pearls
Kokichi Mikimoto, son of a Japanese noodle vendor, single-handedly changed the pearl landscape forever by discovering the best way to produce them artificially. He and his wife struggled in the 1890's to learn the best materials and methods for nucleating (implanting) oysters, disregarding the ridicule of Japan's pearl experts. In 1908 he patented the world's first cultured round pearl.
However, naturals were the most desired gem in the years between WWI and the stock market crash, and women bought all the natural pearls they could afford. The stock market crash and the subsequent pearl crash devalued the high prices of naturals (sound familiar?). Naturals never regained their market share. WWII throttled pearl production, creating huge demand for cultured pearls in the postwar prosperity years.
At its height Mikimoto Company had more than 12 million oysters producing 75% of the world's cultured pearls. The Mikimoto name has been synonymous with very high quality.
The company found that the best luster and appearance occur at.35 millimeters of nacre, and Mikimoto pearls are thicker, since they were left longer in the oyster. The more luster, the higher the value. Perfect round shapes are more valuable than oval or irregular shapes.
BIWA Pearls
Around 1935 pearl experts found that a pearl will form around a piece of soft tissue introduced from another mollusk. These pearls have no artificial nucleus inside. The resulting pearl has an unpredictable flat, pointed, or button-shaped appearance. Coin pearls are also the result of this process. Their luster is excellent. They were first cultured in Lake Biwa in Japan. The name "biwa" indicates the absence of an artificial nucleus.
